Growth performances, nutrient digestibility, ruminal fermentation and energy partition of Thai native steers fed exclusive rice straw and fermented sugarcane bagasse with Lactobacillus, cellulase and molasses.

The study aimed to evaluate the effect of sugarcane bagasse feeding treated with Lactobacillus casei TH14 (L. casei TH14), cellulase and molasses (BG) on nutrient digestibility, ruminal fermentation, energy partition and growth performances of Thai native steers compared to conventional feeding of rice straw (RS). Eight Thai native steers (144 ± 19.5 kg of initial body weight) were randomly allocated to two roughage sources in a completed randomized design: RS (n = 4) and BG (n = 4). The feeding trial lasted for 90 days plus 21 days for treatment adaptation. The results showed that the BG group showed (p < 0.05) greater intake (2.34 vs 2.02 kg/day), total intake (3.90 vs 3.55 kg/day) and average daily gain (0.27 vs 0.23 kg/day) while feed conversion ratio was lower compared to RS group. The BG group had a greater (p < 0.05) organic matter and acid detergent fibre intake than the RS group as well as dry matter and neutral detergent fibre digestibility. The steers fed RS and BG were significantly (p < 0.05) different for total volatile fatty acids and propionic acid at 4 h after offering the diet. The intake of nitrogen (g/day) and apparent nitrogen absorption was significantly (p < 0.05) higher for BG than the RS group while nitrogen excretion in faeces was significantly lower in RS than the BG group. BG group showed significantly (p < 0.05) greater gross energy intake and digestible energy partition when compared to the RS group. In conclusion, feeding BG enhanced feed utilization, growth performance, ruminal fermentation, nitrogen utilization and energy utilization.